Group communication device and method

ABSTRACT

A method for voice based communication between a number of mobile terminals of a telecommunication network, the method comprising the steps of creating a group of said number of terminals and storing group information in each of the number of terminals, recording a voice message in one of the terminals of the group, dispatching the voice message to the terminals of the group from the one of the terminals, and receiving the voice message at least all other terminals of the group. The step of creating a group of terminals further comprises the steps of coupling together a number of mobile terminals, initiating a group creation command from at least one of the terminals, sending predetermined information from terminal to terminal to each terminal of the number of terminals for forming a group information, and transmitting the group information to all of the terminals thus forming a group of the terminals.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/853,214, filed on May 26, 2004, which in turn is a continuation ofU.S. Pat. No. 6,757,531, issued on Jun. 29, 2004, each of which areincorporated by reference in their entirety herein.

TECHNICAL FIELD OF THE INVENTION

The invention relates to a group communication method and a device, amethod for forming of a group of terminal devices and a method forlistening a message between members of an established group and a methodfor sending a message between members of an established group.

DESCRIPTION OF RELATED ART

Advances in telecommunications systems technology have resulted in avariety of systems and services being available for system users. Thesesystems include cellular telephone systems providing mobile telephoneservices. The cellular telephone systems provide services that allowsubscribers to these systems to increase their accessibility and bereachable, potentially at all times, and as long as the subscribersremain in the service areas covered by their systems.

In a cellular system, a person desiring to contact the cellularsubscriber would simply dial the phone number of the cellular subscriberto contact the subscriber at the subscriber's cellular telephone. Aslong as the cellular subscriber kept the cellular telephone powered onthe subscriber would be accessible when located within the coverage areaof the cellular system.

Normally the system sets up a call between the cellular telephone or aso-called mobile terminal and another mobile terminal or a subscriber ofa public switched telephone network PSTN. Dialing the subscriber numberof the mobile terminal or the like sets up a call to the given mobileterminal. In group calls the whole group is called with a single dialednumber, i.e. a group number. A group call is a conference call in whichall participants may talk in turn and hear one another. An individualmobile radio may belong to a plurality of groups programmed into themobile radio. The system keeps a file on the base stations associatedwith the group number of each group. A group call may cover one, severalor all base stations within the area of a mobile exchange or a pluralityof mobile exchanges.

Some mobile networks include short message services, e.g. SMS is abi-directional service in GSM for short alphanumeric messages or data insimilar form. In SMS it is possible to deliver a message to the mobileterminal even during an established call, or to deliver a message usingso-called store-and-forward service, in which the message is stored inthe network, if the mobile terminal is unavailable, and forwardedshortly after the mobile terminal can be reached again. In thetraditional GSM system data services are based on circuit switchedtechnology providing maximum data transfer rate of 9.6 kbit/s fortransparent and non-transparent bearer services for data communication.Along with an increasing data volume, demand for higher transfer rateshas arisen so that the GSM has been developed to include as an extensionthe so-called General Packet Radio service (GPRS) as a packet switcheddata service.

Current solutions use names (e-mail) or telephone numbers (phones) toidentify receivers which the user or an administrator must input to thesystem.

SUMMARY OF THE INVENTION

One drawback of using a cellular system to remain accessible over timeis that cellular airtime charges may be expensive, even for calls madefrom a second party to the cellular telephone. Especially in a familywith many mobile phones the costs will raise quite high. Also the callsbetween the young people will go high, as they usually want to keepcontact quite often and continuously with friends. This same applies tothe people who wish to communicate with the people who are closeregarding work, hobbies and school and want only to communicate withcertain team members. Also the need for a simple communication withsimple terminals exists in order to establish communication betweengroup members. Also to define a group, i.e. to define which members cancommunicate with each other has been quite difficult especially afterone has bought his/her phone. Especially for children there is a realneed for cheap terminals in order to avoid harm after the terminal ispossibly lost or it has been broken due to the fall of the phone. Thereis also a great need for communication between people, in a way not tooverload the network, and, however, so that the subscribers can bereached easily and reliably. Further the younger people who are membersof teams or other groups want to have a common communication terminaland communication way for their group.

The present invention introduces a new method and terminal, preferably awireless communication terminal, for sending voice messages to a groupof terminals as one single transmission from the sending terminal.Preferably a cellular telephone network is used for the wirelesscommunication. Also the present invention provides a method for creatinga group of terminals by coupling together providing a number of mobileterminals and initiating a group creation command to pass each of thecoupled terminals in order to form a group information. The coupling maybe a wireless or physical coupling, and the group information ispreferably sent to a server connected to the network which stores andupdates the group information and after group establishment passesmessages to the terminals of the group.

According to a preferred embodiment of the terminal according to theinvention accessibility is aimed at by a simple user interface design,an approachable simple appearance, a wearable lightweight, small androbust body. The method is a voice messaging delivery system thatenables service providers to offer portable two-way communicationservices over cellular networks. It is possible to use the mobile phonealso as to group mode by selecting a predetermined key for thecommunication within the group. One-key selection makes it easy tocontact the other group members. The invention makes possiblecommunication between terminals, which have a non-conventional keypad,or between the terminals which have keypad or display and the terminals,which have neither display nor keypad for number dialing. The terminaldoes not need to know the actual members of a particular group. Asresult the terminal can be designed to be easy to use and cheap toproduce. It is usable for remote working teams (e.g. field engineering,fishing, agriculture), and e.g. for elderly people's security.

Further the invention is assumed to be suitable especially for youngchildren who have a relatively limited number of reference groups.

According to a first aspect of the invention there is provided a methodfor voice based communication between a number of mobile terminals of atelecommunication network, said method comprising the steps of, creatinga group of said number of terminals and storing group information ineach of said number of terminals, recording a voice message in one ofsaid terminals of said group, dispatching the voice message to saidterminals of said group from said one of said terminals, and receivingthe voice message at least all other terminals of said group.

According to a second aspect of the invention there is provided a methodfor establishing a group of mobile terminals said method comprising thesteps of: coupling together a number of mobile terminals, initiating agroup creation command from at least one of said terminals, sendingpredetermined information from terminal to terminal to each terminal ofsaid number of terminals for forming a group information, transmittingthe group information to all of said terminals thus forming a group ofsaid terminals.

According to a third aspect of the invention there is provided a methodfor sending a message from a mobile terminal to a group of mobileterminals of a telecommunication network, said method comprising thesteps of selecting at the mobile terminal the group of a number ofpredetermined groups, allowing the user of the mobile terminal to speaka message, transmitting the recorded message to a server, storing at theserver information on the terminals of the group of terminals, andfurther transmitting the message to each terminal of said group ofterminals from the server based on said information.

According to a fourth aspect of the invention there is provided a methodfor receiving a message at a mobile terminal of a telecommunication,said method comprising the steps of receiving a voice message comprisinga recorded message, indicating to the user of the terminal that amessage has been received, further indicating to the user of theterminal that the received message is from a terminal belonging to acertain group of a number of predetermined groups, allowing the user togive an input to the terminal, and upon receiving said input playingback the received recorded voice message at the terminal.

According to a fifth aspect of the invention there is provided awireless voice communication terminal for a radio communication network,said terminal comprising a recorder for recording a voice message, meansfor storing a terminal communication group definition defining a numberof terminals belonging to the same communication group, and means forsending said recorded voice message to said number of terminals of saidcommunication group as single transmission from the wireless voicecommunication terminal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a block diagram of a communications network.

FIG. 2 illustrates a schematic diagram of an example of the informationof one group.

FIG. 3 illustrates a block diagram of relevant portions of a terminalaccording to the invention. FIG. 4 illustrates a flow diagram of thecreation of a group.

FIG. 5 illustrates a flow diagram of a further possibility to form agroup.

FIG. 6 illustrates the operating principle of physical contact basedterminal grouping and the data flow within an array of terminals ingroup forming.

FIG. 7 illustrates a message example of the information sent to thecommunication server when forming a group.

FIG. 8 shows an embodiment of the terminal of the inventionschematically.

FIG. 9 shows a flow diagram showing sending of a message.

FIG. 10 shows a flow diagram showing sending of a message.

FIGS. 11A, 11B and 11C show example of the menu shown in the displaywhen a message is recorded.

DETAILED DESCRIPTION

FIG. 1 shows both a circuit and switched telecommunications network. Thenetwork comprises a number of base stations (BTSs) 2, 4 etc. Each basestation has a radio transceiver capable of transmitting radio signals toand receiving radio signals from the area of an associated cell. Bymeans of these signals the base station can communicate with the mobileterminal 5, 6 in the associated cell, e.g. Nokia 2110. The terminals 7,8, 9, 10 represent terminals according to the present invention and willbe discussed in more detail later in this description. Each terminalincludes a radio transceiver, respectively. Each base station 2, 4 isconnected via a base station controller (BSC) 11, 12 to mobile switchingcenter (MSC) 13 which is linked in turn to the public telephone network(PSTN) 14 to other mobile switching centers (not shown). The MSC islinked to service controlling point SCP 16 in order to reach theIntelligent network services. A short message service center (SMSC) 17for providing short message services may be connected to the MSC. Allthe terminals are preferably identified by a phone number or similaraddress information, which are maintained in HLR home location registerthat is stored separately in the network. VLR (Visitor LocationRegister) has the information of the user when the user is outside itsown HLR area. The HLR, which may contain in the MSC subscriberinformation, is enhanced with GPRS subscriber information. The HLRcontains e.g. the following information IMSI, which is the identifier ofthe mobile phone, and MSISDN, which is the basic MSISDN of the MS. Theuser information may include information that the mobile has the voicemessage communication service or the SMS service. By means of thissystem a user of the mobile terminal can establish a telephone call orcorresponding connection to a destination which can be a subscriber inthe PSTN or another mobile terminal in a mobile network or even aterminal in a computer network. The group communication voice calls canbe realized using e.g. server connected to the network and keepingrecord of the groups. Then the user having a mobile terminal dials thenumber for that service or sends a short message from his/her mobiletelephone. The exchange recognizes that the number dialed that theidentifier of the message terminal is a trigger to IN services and thecalls are routed to the intelligent network's database or register. Thenumbers like 0800 and the like are usually routed to the IN. Thefunctionality of exchange (e.g. MSC) will be called service-switchingpoint. Then in the intelligent network there is a register, which hasthe information of the group concerned in order to deliver the messageto the recipients of the group.

The FIG. 1 further illustrates network elements of the GPRS networkstructure. The GPRS network is described in detail in ETSI standard GSM03.60 V6.2.0. In GPRS a packet-mode technique is used for transferringdata and signaling. GPRS's interworking is defined with IP networks andX.25 networks. SMS can be sent over GPRS radio channels. In the networkthe Service GPRS Support Node (SGSN) is keeping track of the mobileterminals' location. The SGSN is connected to the base station system.The Gateway GSN (GGSN) is interworking packet-switched networks likecompany intranets and datanetworks. GGSN is connected with SGSNs via anIP-based GPRS-backbone network. It will be understood that even if it isdescribed as a way of an example GSM and GPRS, the network can be CDMA,W-CDMA, PHS, EDGE, UMTS etc.

FIG. 2 illustrates a schematic diagram of the information that onecommunication group will have in a register. The information may belocated in a service control point (SCP), which is connected to the MSCas shown in FIG. 1. A key to the information in the one group'sinformation is a group identifier (id) 114, which may be provided by thecommunication server in the network. The one who has sent groupinformation to the communication server may be identified in thecommunication server, e.g. usually by the telephone number of the mobileterminal e.g. 0408700321 which can be e.g. father's number 110. Thegroup may be called as a family group. The register will comprise thekey number of the mobile phone 116, which means the key through whichthe calling can occur between the group members. The field showingactivity of the group member 118 is usually on or off depending onwhether the member is reachable or not. Further the used time of theservice of a group member can be followed and statement e.g. minutes andseconds used can be presented in the field 120. It is also possible tocollect the number of the connections the group members have been had.This will be shown in the number of messages sent field 122. The phonenumbers 112 will identify all members of group. The number of the groupmember is shown in field 108. As only one example is shown it will beunderstood that the group does not need to have a separate creator butthe group has been created by collegially.

The table can further include instead of mobile number the address ofthe terminal consisting of the IP (Internet protocol) address or MSISDNnumber combined with the information of the name of the group and/or thenames of the group members. The table may be located also in acommunication server in the IP network in a service server as in FIG. 1,or e.g. in a so called multimedia messaging service center (MMSC) ofNokia. The service may be reached from the GGSN through Firewall orwithout Firewall. Then the functionalities will be group forming andstore and forward capabilities.

Referring now to FIG. 3 therein is a block diagram showing for theinvention relevant portions of a mobile terminal. The structure of a GSMphone is presented in more detail e.g. in international applicationW097/02561. A mobile terminal comprises keys (a keypad), display,memory, microphone, speaker, necessary amplifiers and A/D and D/Aconverters, demodulator, modulator, receiver, transmitter, antenna, andcontroller or CPU for controlling the various functions. Further amobile terminal typically comprises battery pack, (which are not shown)keys for receiving and sending messages, means, like illuminating light,for informing a message received. A terminal according to the presentinvention uses its memory for storing an incoming voice message, anduses its keypad for recalling the incoming voice message from thememory. Preferably the mobile terminal according to the invention maycomprise one dedicated illuminated button for each communication group,and a recorder for recording a message. Further the display is includedto support the menu functions to be used in connection with the use ofthe terminal. The terminal preferably may have compressing means forcompressing the recorded message and adapting means including apacketising means for packetising the compressed voice mail message inthe terminal into data packets for packet-switched transmission as isdescribed e.g. in the international application W09621984, or as knownfrom Nokia 9110 Communicator device. The compressed message is thendelivered to the ISDN address or IP address via a public data network,the GPRS or GSM. The controller (CPU) provides signals to transmitterand receives signals from receiver. The signals may include controlsignals or voice/data communications between MS and cellular system.

For one communication group there is only one button or key if theterminal is constructed by hardware as is shown in FIG. 8. There are sixdifferent group buttons from GR1 to GR6. All interactions to thespecific group in that case are controlled with the one button. Theremay be one dedicated illuminated button for each communication group,whereby the button can be lighted to illustrate that a message has beenreceived from a terminal of that particular group. With one button theuser can form a group, send a voice message to a group, and listen to amessage from a member of a group. When GR1 is illuminating as in FIG. 1,it means that the group has been formed or a voice message is waitingfor playing. The mobile terminal is in one embodiment arranged so thatthe group specific keys will illuminate when the user gets a messagefrom a terminal of that group. The group specific button of the keypadwill illuminate in order to inform the user that a message has beenreceived. The mobile terminal may then have e.g. a separate mode forgroup communication and usual dialing of numbers. A received message isstored and waiting in the voice mail in-box. The terminals according tothe invention according to the invention may be a conventional mobilephone for normal voice or data communication but equipped with the voicemessaging feature or it may be a special voice messaging terminal withless keys and functionalities so that they can easily be used e.g. bythe children.

Further FIG. 3 shows that the messaging terminal has a data transmissionchannel for which it is possible to use a serial bus (RS-232), aparallel bus (Centronics, an infrared interface or a low power RFinterface (LPRF) like so called Bluetooth. Alternatively the messagingterminal can have a magnet and a sensor for detecting the presence ofthe terminal as will be discussed later.

One group member can be a member of many different groups. The mobilephone will have many group ids. Therefore in order to control thememberships of one mobile terminal or the user in the service, adatabase in the communication server for the single user can be created.It is, however, limited usually to the 5 to 10 groups per member inorder to keep the system simple. However, the database of thecommunication server can also collect information of the memberships ofthe users. Then all information regarding the user number may becollected to the communication server. A further possibility is that thecommunication server will have e.g. a column information about eachmessaging terminal's key 116 in connection with the user in FIG. 2. Thenthe messaging terminals may call e.g. by key No. 1 to the group membersidentified by that number in the register, respectively. The id of thegroup transmitted will then inform the communication server located inSCP or in IP network, which group is concerned.

The creation of the groups will be presented in the following. Twodifferent kinds of groups can be made: between simple voice messagingterminals a group can be established. One or several voice messagingterminals or conventional mobile phones can establish a group. One canbuy one, two (or several) terminals or permissions to provide a groupfrom a supermarket or kiosk, form a group or the group is alreadycreated beforehand for those terminals and start using the terminals ingroup communication immediately. The terminal price may include adefined amount of prepaid communication capacity or it can be paidafterwards in the subscriber invoice. If one of the group members isalready a subscriber of the telecommunications network, he can be billedusing this voice messaging service as he has used his telephone. Thisbill can include all the group messaging services used especially when afamily group is concerned. If the voice messaging terminals for groupmembers have been bought and a prepaid amount of usage time is used,then the user can buy more time in order to further use the voicemessaging terminal. One needs to make a contract with the operator notuntil the prepaid capacity is used.

In following the actual physical creation of a group will be explained.In a preferred embodiment creating a group is done by actually gettingall terminals (which are to become members of the group) together in onesingle location and then upon joint decision starting the necessaryactions for creating a messaging group maintaining the group feelingeven when scattered around. When a group of terminals is within, say,one room, the inter-terminal communication needed for grouping can bearranged based on: short distance wireless (e.g. infrared or radio) orphysical contact (galvanic contacts) or contactless based on inductive,capacitive or optical coupling.

In FIG. 4 the main steps for forming a group are illustrated by firstreserving numbers for voice messaging devices in the communicationserver in step 270, selling and buying voice messaging terminals in step272, calling the communication server by at least one of those terminalsin step 274 and informing the group and terminal information to thecommunication server in 276, which may be sent to the server either bymobile terminal of conventional type in step 280 or by voice messagingterminal in step 278. The communication server activates the group ofthe terminals in step 282. Next the terminals can start to communicatewith each other between the predetermined group members in step 284.

FIG. 5 illustrates a block diagram showing how to connect the terminalstogether in order to create a group. Opening IR port cover in stage 240,physically pushing two IR ports against each other enters group mode orany similar physical manipulation related to the IR ports. The userpoints another terminal and presses one of the unassigned buttons orkeys in stage 242. Then the information is transferred between theterminals so that the information in the transmission between twoterminals includes e.g. the ISDN number, key number, and informationthat a group is to be founded. The information from the last groupmember will collect all information from the previous members and sendthe information to the communication server which then gives to thegroup an identifier and sends that identifier to the terminals in thegroup. The receiving terminal is also put to group mode in stage 244.The receiving terminal indicates that it has been invited to a group bya sound signal and an LED blinking sequence in stage 246. The receiverconfirms the group formation by pressing one of the unassigned buttonsduring a timeout (app. 5 s) in stage 248. The group formation betweenthe two terminals is confirmed by a sound signal and the previously darkLEDs start to shine in stage 250. After a while (app. 30 sec.) theshining LEDs turn dark unless group mode is exited before that in stage252. A specific group mode is not necessary here, as new groups can onlybe assigned to previously unassigned buttons. However, the mode would benecessary for confirmation and for providing information on groupstatus. Due to the newly created group the LEDs shine of the terminal isactivated, one is able to send the link to the third (or the nth,n=integer) terminal. The procedure is identical with the one described,however, there is no need to put the sending terminal to group mode asthe previous operations have already activated the group mode.

As physical presence within the new group creates a feeling of unityamong common users, this feeling can be enhanced further by actuallyuniting the group of terminals, too. Physical contact can also be usedto eliminate a group of user interface functions from the user thusmaking the grouping process straightforward and robust. Sincecommunication between individual terminals can be arranged at much lowercost from both hardware and software point of view the option ofphysical contact can be preferred over the short distance wirelessalternatives. The main drawback of physical contact based grouping isthe difficulty of handling large groups, i.e. a stack of terminals mayget difficult to handle without any support like a table. It will beunderstood that other solutions like physical contact, magnetic or otheroptical transmissions, contactless transmissions like radio, (e.g.Bluetooth terminal) which can be done e.g. within 10 m radius. Alsovoice recognition based solutions are possible like using system as inNokia's patent publication EP0959401 relating to voice browsing. Thefunctions like forming a group, sending a message or listening to amessage can be prerecorded and recognized by the terminal when thesecommands are uttered.

FIG. 6 illustrates the operating principle of physical contact basedterminal grouping. In this example a group of 2-n terminals is created.Terminal-1 and terminal-2 forward their identity to terminal-n, whichthen automatically communicates the newly built group structure to thecommunication server over the GSM network e.g. either by utilizing GPRSor SMS (Short Message Service). This action is implemented asself-explanatory as possible, hiding all protocol and GSM relatedcomplexities from the user. When GSM SMS is used, it sets limitations tothe group size as well as lengths of various identifier codes and CRC.One example of a message 300 sent to the communication server in aspecified number address could be as shown in FIG. 7 where the messagehas identifiers FORM and SEND between which the group shall be formedand then the information there are the information which can be seen inthe table of the communication server as in FIG. 2.

Upon detecting the group forming state a terminal microcontroller (CPU)starts transmitting idle characters, i.e. “please standby” messages tothe next terminal in line. This effectively creates a bi-directionaldata path (chain of sensors in one direction and idle data in the other)ensuring that the array remains intact during the grouping process. Thefirst terminal in line requests its user to input the group selection.Once the selection has been given the terminal changes its localcommunication channel transmitter to send identity data rather atregular intervals.

FIG. 6 illustrates the data flow within an array of terminals when agroup is being formed. The first terminal in the array, terminal 1(known to be the first from the fact that it has been connected to aterminal at the front (sensor 42) but it is not receiving data from theback (magnet 40)) keeps transmitting its own identity code T1 (serialnumber, address and/or name) plus a reference to the logical group g1(typically a button code, the communication server needs this data inorder to later send messages assigned to this particular button, icon ortext identifier shown in the terminal user interface) at regularintervals to the next terminal in the array, terminal 2. Terminal 2 addsits own identity T2 and group identifier g2 in the message body andforwards the combined data to terminal 3 and so on. The last terminal n(known to be last in the array by the fact that it is not connected atthe front but it is still receiving valid data at the back) adds its ownidentifiers in the data string and contacts the communication server toofficially form this new group (Group info in FIG. 6). The group may benamed either automatically using the names of the equipment forming thegroup (e.g. name1+name2+ . . . name n) or the user of the terminals canname the group. In the latter case each terminal can then have an ownname for the group (e.g. scouts, football).

An alternative way to form a group and when a communication link likeBluetooth is used as a local data transmission channel, the master ofthe group forming is selected amongst the terminals (when forming thegroup). When the voice messaging terminals are in the group forming modee.g. a Bluetooth connection is selected from the menu of the display ofthe terminals who want to form the group and who are within the area ofthat radio. After a few seconds the master terminal (having a display)shows the names of the terminals that are to be connected in a list. Theintention is that someone of the users checks if the list is correct. Atthe bottom of the list there are two rows (alternatives): cancel andaccept (An example of the display shown in FIGS. 11A, 11B and 11C forsending a message). By pressing the select button when the accept optionis selected the group will be created. In order to communicate betweenthe members of the group outside the range of the Bluetooth radio link(which has about a 10 m range) the information of the group is sent tothe communication server.

A master terminal can be either voted by the terminals using analgorithm that is similar what is used in token buss type networks. Orthe master can be selected by the location of the terminals. In thiscase e.g. the rightmost terminal (in FIG. 6 the one that detects anotherterminal nextby it on the left hand side, but not on the right handside) is the master.

Although not shown the data frames need to be equipped with parity orCRC (Cydic Redundancy Check) data in order to unwanted group membersresulting in data transfer errors.

After receiving all group forming related data from the new groupmembers terminal n prompts this with special sound, light or other userinterface design enabled method. This is an indication to all users thatthe process is complete and the array may be broken. From this onterminal n alone continues the grouping process with communication tothe communication server.

Group information may comprise a string of characters or binary databytes containing the terminal identifier (typically serial number) andthe local group identifier (typically one number or byte of data) ofeach group member, e.g. as shown in FIG. 7. A parity and/or CRC typechecksum may be added to the message to ensure error free communication.The communication server confirms creation of a new messaging group bysending a “new group successfully created” message to each terminalbelonging to the group. Users may start using the group after receivingthe confirmation message.

Grouping can even be fully automatic procedure if terminal's can only doone group at a time. The situation is more complex, however, in mostpractical cases where the user is given the option of communicatingvoice messages with more than one group.

When a group of terminals are stacked in an array for group forming allassociated users are expected to manually select the preferred groupoption in their individual terminals. In practice this can be handled bye.g. tapping a group button according to guidance given with indicators(typically LED's or text/graphic on a display). Voice control can alsobe used, if all terminals' are capable of identifying their owners.

A terminal can detect presence of other similar terminals either throughcontact sensitive switches, galvanic contact, bi-directionalcommunication channel polling or contactless sensing. FIG. 3 shows themagnetic field based contactless method. Use of magnet and sensor (e.g.reed relay, Hall detector) combination provides a reliable and yet ESD(Electro Static Discharge), dirt and water proof means for detection. Asbonus one gets a comfortable snap-hold performance without creating toofragile mechanical locking structures in the terminal housing. This isan alternative for detecting somebody in the vicinity and allowautomatic group formation mode.

An example of terminal local communication channel arrangement ispresented where a communication channel as data transmission channel maybe formed between the terminals e.g. in the situation shown in FIG. 6.The communication channel can be implemented as a single direction pathproviding that the following rules apply: all terminals are arranged inphysically integral array, the last terminal in row (e.g. terminal nthin FIG. 6) gets the responsibility of communicating the groupinformation with the communication server, and successful grouping isinformed to each group member by the communication server. Onestraightforward way of implementing the low-level communication protocolis to use the UART commonly available in microcontrollers. Due to lowamount of data being transferred the data rate need not be very high.Practical data transfer rate with commonly available low pricecomponents is in the area of 1200-19200 bps. There are severalalternatives for implementing the physical communication layer: galvaniccontact, capacitive coupling, inductive coupling, optical coupling.

Alternatives listed above have very differentcost/performance/reliability implications. The galvanic contact isdefinitely the cheapest to implement, yet it is sensitive to dirt andwater and ESD problems may eventually turn the cost performance upsidedown. Capacitive coupling is not very practical at low data ratesrequired in terminal. Inductive coupling would be ideal for data ratesused in the terminal, but unfortunately the number of componentsrequired for a reliable interface is beyond practical limits in aconsumer electronics device. At short distances (<1 cm) opticalinterface (FIG. 8) is straightforward and suitable SMD (Surface MountDevice) components are readily available. Both visible or invisible(infrared) light sources may be used as data transmitters. The drawbackwith this is the terminal casing: transparent windows are needed, thuscausing potential sealing problems.

Making a group with no one can erase all connections related to abutton, i.e. in group forming mode the user presses the button for e.g.3 s without another terminal with which to communicate. In info mode onecan listen the status of the groups. Status may be checked in like theother messages in communication modes, i.e. by short button presses.Status information includes IDs of group members, number of newmessages, time of last new message and so on. In addition this modeenables the user to delete all new messages without listening, reset thebutton. Prompts such as follows are given “Press the group button todelete all messages in this group” and “Press the group button to leavethe group”.

The group-forming mode is exited, when the terminals are separated formeach other.

The SMS including information about group and group member informationmay be sent from the terminal, which has the information of the othermembers of the new group, to the communication server. When establishinga connection between the voice messaging terminals the SMS message maybe sent so that it automatically initiates transmission of a messagethrough SMS, by establishing automatically a connection to the SMSC(SMSC=Short Message Service Center) and inputting information to SMSthat initiates transmission of a message to messaging terminals throughthe SMS. The information sent in the messages may be as presented inFIG. 3.

A mobile originated short message transmission and a mobile terminatedshort message transmission are defined as different services. Shortmessages are transmitted from a mobile terminal to the short messagecenter SMSC. These short messages may be directed to other mobile usersor to subscribers of a fixed network. Short messages are transmittedfrom the short message center SMSC to terminals. These short messagesmay have entered the short message center SMSC from other mobile usersor from other sources. The protocol used between the SMSC and theterminals is called SMTP (Short Message Transport Protocol). The shortmessage center SMSC is given an ISDN number of its own in the numberingdomain of the GSM network, and using this number the mobile terminal candirect a short message to the SMSC. Further in order to reach the saidvoice communication server, said number may be specific to thecommunication server or certain numbers of terminals may be directed tothe voice messaging server services.

The short message service center SMSC is connected to the voicecommunication server so that it is possible to send messages to thevoice communication server. The connection between the short messagecenter SMSC and the communication server may be similar to that in theexisting short message service centers.

The transmission and reception of short messages via the GSM connectionare controlled by the SMSC which is connected to the communicationserver in the case SMS messages are preferred. The functionality of theSMSC is to convert a short message received via the GSM connection intothe communication server. The communication server controls and fetchesthe members of the group by the identifier. The destination addressesare found from the list of the communication server as shown in FIG. 2and short messages including the recorded and compressed voice messageare sent to the group members of the mobile terminals via the GSMconnection. The short message center further may comprise a database inwhich the messages are stored as well as different parameters,conversion tables, etc. needed by the control unit. When a mobile userwants to receive information from an communication server, he sends ashort message, which is, directed (ISDN number) to the short messageservice center SMSC and includes an identifier, which directly orindirectly indicates the group and the key number in question. A directindication includes the group id, and key number and mobile number, forinstance.

The short message is transmitted to the short message center SMSC as anormal mobile originated message. It includes the numbers foridentifying the group members as presented in 300 in FIG. 6 in case thegroup is wanted to be established by the GSM telephone or by the voicemessaging terminal or conventional keypad for dialing digits. Havingreceived the short message SMSC fetches the destination addresses fromthe table on the basis of the group identification code and the SMS hasbeen sent to the destination addresses. The length of a short message islimited, e.g. to 160 characters. The messages longer than this can besent—up to a certain limit—by chaining a few short messages one afteranother. The session control is supported by a database, which maintainsinformation on the user's rights of service, terminal types, serviceprofiles, etc. and on the services of closed groups (e.g. Centrex).

The communication server can be connected to the mobile communicationnetwork via standardized interfaces (telecommunications and signalingconnections).

The voice messages between terminals of the same group is described inthe following. The terminal records a voice message and sends it to theserver. The message is listened when it is convenient for the receiver.FIG. 9 illustrates an alternative of a block diagram of sending amessage between the members of an established group. The user having asimple voice messaging terminal in the first stage 150 presses and holdsthe key of the predetermined group. The terminal gives a signal that itis ready for recording in stage 152. It can be a single peep, byillumination or it can be said e.g. “speak now”. The user speaks then inthe stage 154. If the buffer is full in stage 155, the terminal gives apeep or says “full” in stage 156. Having spoken the message the userreleases the key in stage 158 and the terminal will inform with adifferent or similar signal that recording is successful in stage 160.The message may be sent without the user needing to give any separate‘send’ command. When the message reaches the server, it broadcasts themessage to each member in the group. The length of the message to berecorded may be e.g. 30 s. The message can be sent also to the senderher/himself. However it might easier, if the sender number and thedestination numbers are compared and decided that if the numbers are thesame the message will not be sent the sender. The voice messagingterminal is designed to enable communication within small functionalgroups of e.g. 2 to app. 10 people.

In the following FIG. 10 it is illustrated how the messages can belistened. A message to be listened is indicated e.g. by a blinking LEDin the terminal and an alarm sound, if necessary. The user can at anymoment listen to the next new message or repeat one previously listenedmessage. When the voice messaging terminal informs that a message isreceived, the LED or other kind of lamp of the terminal usually closestto the key determining the group to the user is blinking or signal isgiven in steps 170, 172. In order to listen the message the user pressesthe respective button once in step 174. In next step 176 the terminalplays the message. After the message is played the end signal is givenor blinking is stopped in step 178. A message signal may be differentfor different groups.

If pressed again while listening to a message, the rest of the messageis skipped and the next message will be played. One previously listenedmessage can be repeated. This feature is for being able to e.g. writedown numbers or addresses. The message may be listened repeatedly. Whenthe terminal is idle, the key is double pressed. The previously listenedmessage is played. After listening end signal is heard.

The rate of LED blinking may indicate the number of new messages. Thefaster the rate, the more there are messages. The usage of the terminalmay be such that when pressing once the key it is possible listen to anew or interrupt message, double pressing causes it possible to listento a previous message or from start of a message. By holding the keypressed longer it is possible to record a message.

When somebody leaves the group a system message like “remove” message issent. The server is contacted by the terminal and the register will beupdated regarding that group. The group may be deleted automatically inthe server, if there is less than 2 members. The last members areinformed about this by a system message.

The server uses the group member information in delivering all messagesto appropriate receivers.

A single communication server may be used with very different usergroups (fin vs. work, children vs. elderly etc.) and, similarlyterminals targeted for different customer segments may have verydifferent industrial designs and user interface concepts. In order tomanage this sort of versatility the group forming procedures, associateduser interfaces and communication protocols need to be kept extremelysimple.

Despite using dedicated keys for every group it is possible to provide asolution as described below. This is preferred when the datatransmission channel is radio, e.g. Bluetooth. Here is an example of animplementation of message sending using the aid of menus on the displayof the voice messaging terminal. FIGS. 11A, 11B and 11C showschematically of menu selections in the display when the message isprepared for sending to the group. In the examples underlined text marksthe selected row. User can scroll the menus and lists with the arrowkeys. The Key1 64 may be a Nokia NaviRoller type scroller key as inNokia 7110 mobile terminal. The keys 62 show an example of keys whichcan help the moves in the menu selection. The display 60 contains thetext information from which the user can select the functions likeSelect or Back 66. Other keys like on/off key are omitted from theFigure.

Main menu:

Send message

Listen message

Others

When “Send message” is selected in the list and the user presses aselect button, recording starts and record menu appears:

Recording ready

When recording is done a list of recipient groups appears.

School

Scouts

Football

Pressing the select button now causes the terminal to send the recordedand compressed voice message to the selected group which in this isidentified by the name of Scouts.

When a message arrives, an alert tone is given and the main menu option“Listen message” is activated. Pressing select button now starts thelistening of the received message.

As such, and although the method and apparatus of the present inventionhas been illustrated and described with regard to presently preferredembodiments thereof, it will be understood that numerous modificationsand substitutions may be made to the embodiments described, and thatnumerous other embodiments of the invention may be implemented, withoutdeparting from the spirit and scope of the invention as defined in thefollowing claims. E.g. the stickers can be added to the keys to informthe group identity. The cover of terminal can be changed.

1. A mobile terminal configured to establish a group of mobileterminals, comprising: means for coupling together the mobile terminalto other mobile terminals for establishing the group between the mobileterminal and the other mobile terminals by placing the mobile terminaland the other mobile terminals in close proximity to each other by atleast one of physical contact, magnetic coupling, inductive coupling andcapacitive coupling; and means for initiating a group creation commandfrom the mobile terminal by transmitting information including anidentification of the mobile terminal and a reference to the group to anext terminal in a sequence of the other mobile terminals via at leastone coupling comprising at least one of physical contact, magneticcoupling, inductive coupling and capacitive coupling.
 2. A mobileterminal as claimed in claim 1, comprising: the mobile terminal beingcoupled together with the other mobile terminals by a directcommunication distance; and the mobile terminal and the other mobileterminals are detected to be in a group forming state before initiatingthe group creation command by the mobile terminal.
 3. A mobile terminalas claimed in claim 1, wherein the mobile terminal transmits saidinformation to a communication server connected to a telecommunicationnetwork.
 4. A mobile terminal as claimed in claim 1, wherein the mobileterminal and the other mobile terminals are mobile radio terminals.
 5. Amobile terminal as claimed in claim 2, comprising upon detecting beingin a group forming state: means for transmitting idle character messagesfrom said mobile terminal to a mobile terminal of the other mobileterminals in a sequence, creating a bi-directional data path between atleast the mobile terminal and one of the other mobile terminals of thegroup; and means for causing said mobile terminal to request a user toinput a group creation mode, and upon receiving said input causing saidmobile terminal to send identity data to at least one of the othermobile terminals within the bi-directional data path.
 6. A mobileterminal as claimed in claim 5, wherein a key on said mobile terminal ispressed to provide the group creation.
 7. A mobile terminal as claimedin claim 6, wherein the key relates to the formed group.